|
Blood vessels take blood from
the heart and back again in order of arteries, arterioles, capillaries,
venules, and veins.
Each type of blood vessel has
particular features that help it do its job efficiently.
| Blood Vessel |
Functional
Characteristics/Description |
| Arteries
|
Thick
walled to withstand pressure, elasticated tissue to allow changes
in pressure, smooth muscle to allow changes in vessel diameter. |
| Arterioles |
Large
amounts of smooth muscle to control vasodilation and vasoconstriction
to regulate blood pressure and flow - particularly during exercise. |
| Capillaries |
Single
layer epithelial cells allow red blood cells to squeeze through
the wall. Large surface area of capillaries increases gaseous
exchange. |
| Venules |
Return
blood to veins from capillaries. Not very elastic or thick walled
due to lower pressure. |
| Veins |
Increase
in thickness as they approach heart, contain valves to prevent
backflow. |
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